The only time Astarion sort of offers "his gift" himself is when the player starts reading "morality" and chooses to branch the dialog through swearing.
Morality - and what did you learn?
Scolding - what was I supposed to learn?
Provocation - how to love me?
Scolding - and what makes you think I haven't learned? So it's over?
The only option for reconciliation - No, we'll work it out.
Then the poor guy grabs his heart with trembling hands and says, "you're the one I love, the one I want to be with".
It is not good.
Not good at all. This dialog reminds me of some chauvinistic anecdote about a stupid woman pestering a poor guy with constant, "Do you love me???? No, you don't love me!!!! You said... (*the anecdote here has to be some funny stuff that caused the tantrum)". Only Astarion doesn't react like the man in the anecdote, and Tav is even nastier and meaner than the stupid heroine of the anecdote is supposed to be. It's clear that BG3 has its own very strong points (mocap, great voice acting, the very presence of such a character as Astarion) and no one expects for their Tav lines of Planescape: Torment or Disco Elysium level, but still, the gap between the intelligence of the character, which is expressed through their lines, and the intelligence of a living person, who is asked to choose lines for the character, should not reach such cosmic values.
But I thought about how wonderful it would be to hear Astarion's line, "You're the one I love, the one I want to be with," but spoken in a different way, without grabbing his heart with trembling hands, but with a warm gaze, as he wished. In response to a loving retort from Tav. And then Astarion moves on to "That's what you want, isn't it? To be mine? Forever?" It turns out that in that case, he's offering his own gift.
"I want to be with you, my love. I love you Astarion and I wanted you to have everything that makes you happy in this world."
+1
I like it a lot. To have everything that makes you happy in this world. It totally brings out my character's whole motivation, her goal and her dream. My "main quest" of the whole game.